[GRASS-user] Virtual Mosaic import with r.external

[Jeshua Lacock]

> On Dec 24, 2014, at 5:10 PM, Jeshua Lacock <jeshua at 3DTOPO.com> wrote:
> 
> I was following along the Large raster data processing wiki with great interest:
> 
> My question is, when tiles are merged in GRASS using a virtual mosaic created with gdalbuildvrt, will transparent map collars be preserved?  I see the man page for r.external talks about the requirement to build a mask or use r.mapcalc, but I don’t understand how I would apply that to a virtual mosaic. Is 

It appears that GDAL_TIFF_INTERNAL_MASK may be just what I need to use. I wonder if that option is respected using r.external? Thanks!